According to the pontificals, he was the son of one Rufinus, and a native of Aquileia. He had served the church among the clergy at Rome many years under Adrian and Antoninus Pius, when, according to Tillemont, in the fourth year of the reign of the latter he succeeded Saint Hyginus in the papacy in 142. He condemned the heresiarch Valentinus, and rejected Marcion, who came from Pontus to Rome after the death of Hyginus, as we have related elsewhere. The conflicts which Saint Pius sustained obtained him the title of martyr, which is given him not only in Usuard’s Martyrology, but also in many others more ancient; though Fontanini, a most judicious and learned critic, strenuously maintains, against Tillemont, that he died by the sword. He passed to a better life in 157, and was buried at the foot of the Vatican hill on the 11th of July.